Samsung has announced the shipping of its 940UX, the first display with USB input. We are talking about the US version, while Europe will wait a bit longer.
This 19 inch display uses its own hardware and CPU power without the need for a dedicated internal video card. According to the Samsung press release, even a notebook can run six displays if it has enough USB's and enough processing power.
The standard DVI and VGA ports are still there if you want to use it as a plain display. Display currently only does USB with Windows XP. The suggested retail price is $379.